Modern-day handheld communication devices are capable of performing a multitude of tasks ranging from voice communication, browsing the Internet, creating and editing documents, and sending e-mails. All of theses tasks require that the user enters characters and operates the device via some kind of input means.
A typical input mean in a handheld communication device, such as a mobile phone, is a numerical keypad. Since handheld devices often are quite small in physical size, the keys on the numerical keypad must also be small and often placed very close together. This makes entering characters using a numerical keypad a cumbersome and error prone operation.
To mitigate some of the effects discussed above a full QWERTY-keypad (one key per character), with adequate spacing between the keys, could be used. However, fitting a full QWERTY-keypad with adequate spacing between the keys on a handheld device is not possible without making either the keys tiny, or making the device larger enough to accommodate all the keys. Neither of these approaches is desirable from a user-friendliness point of view.
Document WO2007/042115 discloses a keypad that uses dual operation keys, or twin keys, to mitigate some of the effects discussed above. Each twin key may be used to select one of two possible characters, thus reducing the total number of keys needed, while still offering a full QWERTY-keypad, considerably. However, the space (footprint) needed on the devices casing to accommodate the twin keys are still quite large, making the device bulky. Reducing the size of the twin key, or placing them tighter together, is not an option since it would seriously effect the user-friendliness and make the input operation more prone to errors.
Therefore, it is a necessity to provide a user-friendly full QWERTY-keypad, comprising keys having a small footprint, for handheld communication devices, which do not consume precious space on the devices casing.